Eucalyptus trees provide welcome shade on Batiquitos trail

BATIQUITOS LAGOON

Before you go:
Take a look at the Batiquitos Lagoon Foundation's Web site at
batiquitosfoundat...
. You can download lists of birds, plants and animals, as well as a self-guided trail guide and maps of the lagoon trail.

Trail head:
There are several entry points to the main lagoon trail. The easiest starting point is near the lagoon's visitors center, open 9:30 a.m. to 12:30 p.m. Monday-Friday, and 9 a.m. to 3 p.m. Saturday and Sunday.

Directions:
Exit Interstate 5 at Poinsettia Lane, going east. Turn right onto Batiquitos Drive, then right again onto Gabbiano Lane, and park in the designated spaces at the end of the cul-de-sac.

Rules:
Dogs are allowed only on leashes. No bicycles or horses are allowed.

Trail length:
The main lagoon trail is a little less than 2 miles long from one end to the other, making for a 3½- to 4-mile round trip. Allow at least 1½ to 2 hours.

Difficulty:
Easy.

Batiquitos Lagoon Trail in Carlsbad is one of the prettiest pathways along a coastal wetland because of an invader — the eucalyptus tree.

Dozens of the trees rise high above the trail, providing welcome shade as well as their distinctive beauty.

The eucalyptus tree is native to Australia but has naturalized throughout California. Its leaves and seed pods contain oils that prevent other plants, including native coastal sage scrub, from growing underneath them, according to the self-guided trail guide that accompanies 25 markers along the lagoon trail.

They're not all bad, however. The guide also points out that the eucalyptus trees have become homes. “Great blue herons and both snowy and great egrets build their nests in trees,” it states.

The trail guide, which can be picked up free at the trail head, makes this nearly 4-mile-round-trip walk even more interesting. It points out geology lessons through sediment layers; identifies several native and non-native plants; discusses mud-flat ecology (where worms and clams, snails and shrimp are all food for birds and other animals); and lists several birds and fish commonly found there.

More than 180 species of birds have been sighted at the lagoon. You might spot any time of year the herons and egrets wading in the shallow waters. The American avocet is one more wader.

In winter, look for terns plunging for fish, and mallard and green-winged teal ducks. The endangered California least tern comes in late spring and summer on its migratory route.

There are five man-made sand nesting sites on the other side of the lagoon for the least tern and Western snowy plover.

The California Fish and Game Department manages Batiquitos Lagoon as an ecological reserve.

The Batiquitos Lagoon Foundation, a nonprofit run by volunteers, helps to preserve and enhance the lagoon through educational programs and events.

The foundation reports that nearly 200 prehistoric sites dating back 8,000 years have been found at the lagoon. The sites show that marine shellfish were harvested from the lagoon for thousands of years.

The lagoon is a little farther from the main trail than, for example, the trail at San Elijo Lagoon a bit farther south, so you might need good binoculars to spot some of the waterfowl.

But you'll have those eucalyptus trees to view, along with glimpses of the expertly manicured greens of the Four Seasons Aviara golf course. And the trail is flat and wide, so it's an easy pathway for wheelchairs and strollers.

Smell the aromas of the sage, sweet fennel and lemonade berry, as well as a scent that can be described as rotten eggs. The latter is caused by marsh bacteria that draw sulfur from dead plants and animals in the lagoon to decompose the dead materials. “If you smell rotten eggs, just be patient. It's good ol' bacteria at work,” reads a plaque along the trail.

Once a year, kayakers can go onto the lagoon as part of an annual cleanup.